Empty script tags cause trouble.

If a shorthand empty script tag is included anywhere in the document, most
HTML editors get into trouble, especially the syntax highlighting is all
wrong. So the next sample doesn't work well:

<script type="text/javascript" src="somescript.js" />

While the normal method works as expected:

<script type="text/javascript" src="somescript.js"></script>

As worst of all: Internet Explorer fails on this piece of code as well, yet
Mozilla and Netscape act as I think they should. Therefore I would very much
like to know why this isn't handled properly. Is this not valid XHTML, or is
this a bug in the different types of software? The w3 validator does not
return any errors, so I can only think of 2 possible causes:

1: a bug in a lot of editors and even browsers
2: a bug in the w3 validator

Or might there be other things I didn't think of?